1. Field of the Invention
This invention relates to refining of petroleum and more particularly refers to a new and improved method and apparatus for treating crude oil to convert it almost entirely into liquid and gaseous hydrocarbons.
2. Description of the Prior Art
In the processing of crude oil in a petroleum refinery, the crude oil is first fed to an installation for atmospheric distillation. As described, for instance, in the book "Die Verarbeitung des Erdoels" -- Petroleum Processing -- by Riediger, Springer-Verlag 1971, and shown on page 953 in FIG. N/6, the installation for atmospheric distillation is followed by a further installation for vacuum distillation as well as individual facilities for the cracking of carbon compounds. Even so one obtains 20%, based on the weight of the crude oil used, of low-quality and hard to process residues. These residues are hard to use particularly for the reason that their sulfur content is high. To also desulfurize these residues and to process them into light hydrocarbons, hydrogenation processes must be employed which are expensive because of their large hydrogen requirements, and are therefore uneconomical. For this reason, in the operation, conditions for the atmospheric distillation and particularly its sump temperature are chosen so high that as little residue as possible is required to be drained from the bottom of the distillation tank.